Split frame for rotary vacuum mold unit

Abstract

An auxiliary double frame for a rotary vacuum mold unit or rotary thermoformer has a center auxiliary frame member and one or more auxiliary transverse frame members. The thermoformer has several identical frames that carry the plastic sheet workpieces from a load/unload station to a heat station or an oven, then to a vacuum molding station, and then to the load/unload station where the molded product is removed and replaced with a blank plastic workpiece. A center auxiliary frame member is mounted onto the front and back main frame members, and can be positioned on center or to the right or left of the center of the frame. Auxiliary transverse frame members are employed with the standard transverse clamping frame members. Pneumatic cylinders mount on the transverse clamping frame members and on the longitudinal frame members for operating pinbars. This system permits two or more molds to be employed at the same time.

What is claimed is: 
     
       1. A split auxiliary frame for a rotary vacuum molding thermoformer in which a plurality of identical main frames are arranged in a carousel to carry thermoplastic workpieces from a loading station to a heating station, thence to a vacuum molding station, and thence to an unloading station, wherein each of said main frames has a back frame member, a front frame member, and left and right side frame members together defining a horizontal rectangular configuration; the auxiliary frame comprising a center auxiliary frame member having ends removably mounted onto said front and back main frame members and disposed parallel to said side frame members; a back transverse rail and a front transverse rail each having left and right ends adjustably mounted onto said left and right side frame members respectively and disposed parallel to said front and back frame members; a first pair of longitudinal rails disposed to the left of said center auxiliary frame member and a second pair of longitudinal rails disposed to the right thereof, and each supported between said back and front transverse rails; and clamping means disposed on said longitudinal rails and on said transverse rails, for removably clamping said workpieces in said frame as the workpieces are carried from the loading station to the unloading station. 
     
     
       2. A split auxiliary frame according to claim 1 wherein said center frame member includes front and back channel mounts affixed respectively on said front and back main frame members, and front and back feet removably secured onto the channel mounts such that the position of the center frame member is adjustable along the length of said channel mounts. 
     
     
       3. A split auxiliary frame according to claim 1 wherein said center frame member includes a rail and a channel slide that is slidably adjustable along the length of the center frame member rail, and at least one auxiliary transverse rail that is supported at one end in said channel slide and at its other end in one of said side frame members. 
     
     
       4. A split auxiliary frame according to claim 1, wherein said front and back transverse rails are each in the form of separate left and right transverse rail halves, with left ends of the right transverse rail halves supported on said center frame member and with right ends of the left transverse rail halves supported on said center frame member. 
     
     
       5. A split auxiliary frame according to claim 4 wherein said center frame member including two side-by-side channels, with the left ends of the right transverse rail halves being adjustably supported in one of said channels and the right ends of the left transverse rail halves being adjustably supported in the other of said channels. 
     
     
       6. A split auxiliary frame according to claim 4, further comprising connector means for uniting the left and right ends of associated ones of the right and left transverse rail halves when said center frame member is removed, so that the auxiliary frame can accommodate a large workpiece. 
     
     
       7. A split auxiliary frame according to claim 6, wherein respective facing ends of said right and left transverse rail halves include a flange extending in a transverse plane with a gap being defined between the flanges of the respective transverse rail halves; and said connector means includes a pair of parallel plates with a space therebetween to fit over said flanges and to fasten thereto, and a spacer affixed between said plates and dimensioned to fill said gap between said flanges.